What Normal said. 99% of the time a 120vac 20 amp receptacle isn't needed and you'd be hard pressed to find a typical power tool that has a 20 amp plug on it. Code allows you to use 15 amp receptacles on a 20 amp circuit as long as there are two or more of them, and a standard duplex receptacle counts as two. Specification grade receptacles will cost more than the usual cheap ones you find in the bins at the big box store but they're made of more durable materials.